We investigate the causal effect of patent rights on cumulative innovation, using large-scale data that approximate the … patent universe in its technological and economic variety. We introduce a novel instrumental variable for patent invalidation … that exploits personnel scarcity in post-grant opposition at the European Patent Office. We find that patent invalidation …

We investigate the causal effect of patent rights on cumulative innovation, using large-scale data that approximate the … patent universe in its technological and economic variety. We introduce a novel instrumental variable for patent invalidation … that exploits personnel scarcity in post-grant opposition at the European Patent Office. We find that patent invalidation …

. Where licensing fails, follow-on innovation is blocked unless firms gain FTO through patent invalidation. Using large …We study the blocking effect of patents on follow-on innovation by others. We posit that follow-on innovation requires … freedom to operate (FTO), which firms typically obtain through a license from the patentee holding the original innovation …